Use of near Infrared Spectroscopy for the Identification of Coffinite and Uranothorite

Near infrared (NIR) spectroscopy was performed on a synthetic coffinite–uranothorite series and natural coffinite. The NIR spectra revealed a characteristic band at 1135 nm, allowing the identification of coffinite–uranothorite minerals within uranium ore environments. These minerals can be identified even in some complex mixtures (host rocks containing coffinite and several infrared reactive minerals such as clay minerals) or samples with low structural uranium amounts (e.g. Th0.8U0.2SiO4). Well-resolved on field spectra, the 1135 nm band could be used as a powerful tool for uranium ore exploration.